What’s the reasoning behind the -> to denote type annotations in the SDL?

[jonaird]

It seems a bit unusual and also a bit awkward to type. Something like the way Java or Typescript does it might be a bit more natural? Is it to enforce a type on all fields?

[elprans]

SDL syntax is essentially abbreviated DDL (with verbs stripped). We use -> to annotate the result type of a schema construct. Functions, for example, also use -> to specify the return type. Historically, we chose ->, because : was conflicting, and because -> also resembles a graph link, i.e type Foo { link bar -> Bar }.